Somatic copy number alterations have prognostic impact in patients with ovarian clear cell carcinoma

Ovarian clear cell carcinoma (OCCC) is a chemotherapy-resistant epithelial ovarian cancer with poor prognosis. To identify genomic alterations involved in the development of OCCC, we analyzed somatic copy number alterations in OCCC using comparative genomic hybridization (CGH). Here we showed that the chromosomal regions 8p11.21, 8p11.22, 12p13.31 and 20q13.2 were amplified in OCCC. We also demonstrated that small segments in the chromosomal regions 3q26.1, 4q13.2 and 22q11.23 were deleted. Kaplan-Meier survival analyses revealed that patients with amplification within 8p11.21 or a deletion within 3q26.1 had a shorter progression-free survival (PFS) time than those without such alterations. In addition, patients with amplification in three of the four chromosomal regions 8p11.21, 8p11.22, 12p13.31 and 20q13.2 had shorter overall survival (OS). We also demonstrated that amplification of 12p13.3 or three of the four chromosomal regions 8p11.21, 8p11.22, 12p13.31 and 20q13.2, or a deletion in the chromosomal region 3q26.1 was associated with chemotherapy resistance. Our findings suggest that copy number alterations in 8p11.21-22, 12p13.31, 20q13.2, 3q26.1, 4q13.2 and 22q11.23 are critical for the development and survival of OCCC.